Wards



1. MCC. EDWARDS.

IMPULSE STARTER.

APPLICATION FILED IAN, 2|. 1920.

1,371,023. `Patented Mar. 8,1921.

2 SHEETS-SHEET I.

,fr/ven for; James MCCashdz/Jaas, y

ttorney.

J. MCC. EDWARDS. IMPULSE STARTER.

APPLICATION FILED .IAN.2I, 1920.

Patented Mar. 8, 1921.

2 SHEETS-SHEET 2.

[nz/er: tor. James M6006?? Edwards, 6g

Attorney.

NONRIS PETERS, INC., LITHO.. WASHINGTON, D C` UNITED STATES PATENT oFFlCE.

JAMES MCCOSH EDWARDS, OF CEDAR HEIGHTS, IOWA, ASSIGNOR TO ASSOCIATED MANUFACTURERS COMPANY, OF WATERLOO, IOWA, A CORPORATION OF IOWA.

IMPULSE-STARTER.

Specification of Letters Patent.

f y:PatentenMar. s, 1921.

Application filed January 21, 1920. Serial No. 352,929.

To all whom t may concern.'

Be it known that I, JAMES MoCosrI ED- WARDS, a citizen ofthe United States of America, and a resident of Cedar Heights, Blackhawk county, Iowa, have invented certain new and useful Improvements in Impulse-Starters, of which the following is a specification.

My invention relates to improvements in impulse starters for electrical current generators, particularly to such as are employed in connection with magnetos used to generate sparking currents for internal combustion engines, and the object of my improvement is to render certain the operation of such a starter in causing the magneto to supply an adequate igniting spark while the engine shaft is being turned over at a relatively low speed of rotation.

I have successfully accomplished this object b the mechanism which is hereinafter described and claimed, and which is illustrated in the accompanying drawings, in which Figure 1 is a side elevation of -a magneto equipped with my improved impulse starter, and Fig. 2 is an end elevation of the magneto and said device, with the Cardan? coupling member removed. Fig. 3 is a perspective view ofthat extremity of the rotor shaft and of the magneto shoulder which respectively are connected to or coact with parts of the driven member of the impulse starter, and Fig. 4 is a perspective view of the complete driven member of said'startery which is associated therewith; Fig. 5 is a perspective view of said driven member with the movable weights removed, and Fig. 6 is a perspective view of the opposite face of the driven member; Fig. 7 is an end elevation of said driven member and of said weights as mounted thereon, with the magneto shoulder in place therein in cross-section. Fig. 8 is a perspective view full size, of one of the said weights; Fig. 9 is a perspective view of the driving member including the inner separating ring; Figs. l0 and 11 are end elevations showing the inner parts of the driving member, including the helical Springs, the parts being in the positions respective to the incompressed and to the compressed states of the helical driving sioned, and lwhen the driven-member is released from the driving member and the driving spring compressed.

Similar numerals of reference denote similar parts throughout the several views.

In the employment of an electrical current generator, especially the type called a magneto designed for intermittently supplying ignition sparks within the combustion-chamber of an internal combustion engine, and in which the driving-shaft of the engine, by means of suitable connections, rotates the rotatable element of the generator, in the starting of the engine, the relatively slow rotation of said driving-shaft is insufficient to cause the generator to furnish any or at least, an efficient ignition spark.

' Many impulse startersl have been designed to obviate this insufficiency, but often these devices fail to give satisfaction in continuous and reliable action, hence my production of a device of this type, which under the necessary conditions of use has proven practicable and uniformly successful.

It has also been my object to provide a device comprising a minimum of parts, simple, of inexpensive construction, suitable for interchangeable manufacture, completely inclosed in its contained mechanisms, and hence easily assembled, disassembled, repaired and lubricated.

My improved impulse starter may be employed with and for any of the well known kinds of magnetos, so I have illustrated in Figs. l and 2 merely a generalized form l thereof, whose rotor has the usual coned shaft 3 terminating in a threaded part 4 to take a securing nut 34.

An annular plate 2 is fixed to the magneto l concentrically about the shaft 3 and has a projecting semi-cylindrical projection 5 with oppositely positioned shoulders parallel with the axis of the shaft.

A driven member 6 of cylindric form has a diametral web or diaphragm 3 integrally supported on a hub 7 which has an interiorly coned axial hollow to seat it upon the conic part of the shaft 3 to which it is splined. A hollow cylindrical body 11, of greater diameter than said hub v7, projects concentrically from the opposite or outer face of the web 8 and has near its outer end an outer annular shallow groove 13 to receive a spring split-ring 37. j

The Outer edge of the driven member 6 has equidistant rectangular notches 12 for a purpose to be described. The web 8 has two radially elongated slots 9 positioned oppositely on the same diametral line and extending from near the body 11 to the inner wall of the driven memben Equidistant between the slots 9 are pairs of pins 10 projecting from the inner face of the web 8, the ins being placed in lines parallel with the iameter along which the slots 9 are eX- tended.

Referring particularly now to Figs. 7 and 8, the numeral 14 denotes a pair of like arcuate weights whose outer peripheral ed es conform in curvature to the interior Wa ls of the driven member 6, and which have arcuate recesses 17 central, with their transversal inner edges interrupted by offset shoulders 18. The two transverse edges of each weight at either side of the recess 17 are interrupted by elongate notches 16 of a width suitable to slidably t over the adj acent pins 10 of each pair, the notches being elongated in the same direction as the alinement of the pairs. The arcuate recess 17 of each weight conforms to the circle of the semi-cylindrical projection 5 when the latter is positioned between the weights, the hub 7 being mounted on the shaft 3. Cylindrical pins 15 are fixed at opposite locations in the weights 14, projecting from the outer faces of the weights through the slots 9 of the web 8 and beyond the web for a suitable distance.

Referring t0 Figs. 9 t0 13, the numeral 21 designates a fiatly cupped circular driving member having a hollow hub 25 rotatably mounted on the cylindrical projection 11 of the driven member 6, and retained removably thereon by the removable split-ring 37 in the annular groove 13 on the latter. Op-

j posite parts of the outer wall of the hub 25 are removed to provide cam faces 26. The hub 25 is surrounded by a concentric annular trough 31 opening toward the driven member 6. A stud 29 is fixed in said groove at an appropriate location relative to the cam face 26 of the hub 25. In said groove 31 are mounted a helical compression drivingspring 32 and a shorter helical cushioning compression-spring 33.

The numeral 22 denotes an annular plate which covers the annular trough 31, retaining said springs in place. This plate is of less diameter than the hollow of the driving member 2l, and has equidistant peripheral projections 24, the latter fitting into the rectangular notches 12 of the driven member 6 so that the plate interlocks and rotates with the latter. The plate 22 has a fixed stud 28 projecting into the annular trough 31 and which is interposed between the springs 32 and 33, the fixed pin 29 0n the driving member being interposed between the other adjacent ends of said springs. As the hub 25 projects beyond the annular plate 22, the pin projections 15 of the weights 14 ride upon the cam 26.

The operation of my improved impulse starter will be readily understood. The engine may, by means of any suitable power transmission means, impart rotation to a shaft 36 on which is fixed a coupling member 35 adapted to mate with projections 27 on the driving member 21, forming the wellknown Cardan coupling. It is obvious that when the engine-shaft is turned over slowly, as when crankin it in starting the engine, the driving mem er 21 will be rotated at a relative speed. As at relatively slow speeds of rotation 0f the driven member 6, the inclosed weights 14 are not acted upon to be moved radially outwardly by centrifugal force, as the driven member turns, propelled by the driving member 21 acting against the spring 32 through the projection 29 without appreciably compressing said spring, the weights drop toward the axis of the driven member, and their inner shoulders 18 engage the shoulders of the magneto projection 5, which locks and holds the driven member 6 fiXedly. The continued rotation of the driving member projection 29 then compresses the spring 32, as shown in Fig. 11. As the cam 26 turns under the weight projections 15, the latter are caused to ride from the cut away parts 26 upon the circular faces of the cam, the weights thus being propelled radially outwardly to disengage their shoulders 18 from the fixed projection 5 at the moment when the spring 32 is fully compressed. The released spring 32 then suddenly forcibly reacts upon the projection 28, giving a quick reactional impulse to the driven member 6, whereby the rotatable element 0f the electric generator is rotated with a suitably rapid movement to furnish an intense ignition spark. The two weights 14 act in this wise successively, causing sparking twice during each rotation of the driven member, but as the rotation of the engine shaft is quickly accelerated, the rotatory speed imparted to the driven member by the driving member 21 becomes such as to shift the weights 14 outwardly radially by centrifugal force, so that their shoulders 18 miss the shoulders of the magneto projection o, and the driving and driven members actas one in the ordinary-production of electrical current by the magneto. Iii the rotation of the engine shaft falls beyond a certain limit, the weights move inwardly, and their coaction with the driving spring 32 recommences to produce the necessary quick impulses to the rotor oi the magneto. It will be observed that the other spring 83 is provided to cushion the thrust given the projection 29, rendering this action more equable.

The merit of my improved device rests principally in the employment therein of the radially movable weights 14, of which one or more may be used as desired, for the radial movement of the weight is direct, quickly responsive and equable, causing the device to work in quick response to the spring action, without any failures in normal operation.

Having described my invention, what 1 claim as new, and desire to secure by Letters Patent, is:

1. An impulse `starter for an electrical current generator, comprising a driven member adapted to be secured to the rotatable part of the generator; a driving member rotatably mounted on the driven member; fixed engaging-means mounted within and concentric with the driven member; a weight slidably mounted upon and engaged at its opposite ends with the driven member for radial movements only relative thereto and having engaging-means adapted for engagement with said fixed engagingmeans when in its inmost position, and also having a projection; said driving member having a cam upon which said projection rides; a spring; means on the driven and on the driving members for setting the spring at tension by rotating the driving member in advance of the driven member while the engaging-means on said weight is engaged with said fixed engaging-means; said cam actuating said projection to move the weight outwardly to release the engaging-means thereof from said fixed engagingmeans, thereby releasing said spring from tension to impart a relatively rapid rotation to the rotatable part of the generator.

2. An impulse starter for an electrical current generator, comprising a driven member adapted to be secured to the rotatable part of the generator; a driving member rotatably mounted on the driven member and having a cam within an annular spring-seat; a helical spring mounted in said spring-seat; said driven member having guide pins and a radial slot, a weight mounted on said driven member having a projection traversing said slot and extending therefrom to ride upon said cam,said weight having recesses receiving said guide-pins; means on the driving and on the drivenmembers for setting the spring at tension by rotating the driving-member in advance ofthe driven-member; and engaging-means iixedly supported within the driven-member adapted to hold said weight ixedly to prevent rotation of. the driven member while the spring is being set at tension, said cam operating on said projection and weight to move them radially outwardly to release them from said engaging-means, releasing the driven member to be rapidly rotated by reaction of said spring.

8. An impulse starter for an electrical current generator, comprising a driven member adapted to be secured to the rotatable part of the generator; said driven member having a web provided with oppositely located radial slots and with guidepins positioned oppositely and intermediate said slots, like weights of segmental form positioned on said web op ositely, having projections extended throug said slots and having recesses inclosing said guide-pins whereby the weights are permitted only radial movements relative to ythe driven member, said weights having arcuate inner edges provided with engaging shoulders, fixed engaging shoulders on said generator positioned concentrically within the drivenmember to be engaged by the engaging shoulders on said weights in turn when the weights shift to their inmost positions; a driving member rotatably mounted on the driven member and having a cam upon which the projections of said weights ride; a spring; means on the driven and on the driving members for setting the spring at tension by rotating the driving member in advance of the driven member; said cam operating upon said projections to shift said weights radially, releasing their engaging shoulders from the engaging shoulders on the generator to release the driven member therefrom and the spring from tension.

4. An impulse starter for an electrical current generator, comprising a hollow driven member concentrically secured to a rotatable part of the generator and having a transverse partition provided with radial slots; a semi-cylindric body fixed on the generator casing and extended concentrically into said driven member to provide oppositely-located longitudinally-directed shoulders, like arcuate planar weights positioned oppositely within the driven member abutting upon that wall of said partition adjacent t-he generator and having fixed pins extended through the slots in the partition, the inner edges of the weights having ratchet-detents to engage the shoulders on said semi-cylindric body when the weights are in their inner positions; a driving member rotatably mounted on said driven member, said driving member having a cam on which said fixed pins ride; a spring; means on the driven and on the driving members for setting the spring at tension by rotating the driving member in advance of the driven member While the detents on said Weights are engaged with the engaging shoulders on said fixed body; said cam actuating said pins to move the Weights radially outwardly to release the detents thereof from the fixed body, releasing the spring from tension to impart a relatively rapid rotation to the rotatable part of the generator. 10

Signed at Waterloo, Iowa, this 22nd day of Dec. 1919.

JAMES MCCOSH EDWARDS. 

